INTRODUCTION
The Social Vulnerability Index (SVI), developed by the Centers for
Disease Control and Prevention’s Agency for Toxic Substances and Disease
Registry (CDC/ATSDR), is a tool designed to identify communities at
increased risk during public health emergencies. Understanding social
vulnerability allows policymakers, emergency response planners, and
public health officials to allocate resources and interventions more
effectively, ensuring that those who are most in need receive
appropriate support.
WHAT IS SOCIAL VULNERABILITY?
Every community must prepare for and respond to hazardous events,
whether a natural disaster like a tornado or a disease outbreak, or an
anthropogenic event such as a harmful chemical spill. The degree to
which a community exhibits certain social conditions, including high
poverty, low percentage of vehicle access, or crowded households, among
others, may affect that community’s ability to prevent human suffering
and financial loss in the event of a disaster. These factors describe a
community’s social vulnerability.
THEMES AND CALCULATIONS
The SVI ranks each census tract on 16 social factors, grouped into
four related themes, each representing a different aspect of social
vulnerability:
Socioeconomic Status:
- This theme includes indicators such as poverty, unemployment,
housing cost burden, no health insurance, and no high school
diploma.
Household Characteristics:
- This includes metrics related to age (over 65 and under 17 years),
disability, single-parent households, and English language
proficiency.
Racial and Ethnic Minority Status:
- This theme assesses the proportion of all racial/ethnic minorities
other than Non-Hispanic Whites.
Housing Type and Transportation:
- Indicators like multi-unit structures, mobile homes, crowding, no
vehicle access, and group quarters are included, highlighting potential
barriers in evacuation or shelter-in-place scenarios.
For each theme, the SVI uses U.S. Census data to score and rank each
tract relative to others, considering these factors collectively to
identify areas with potentially greater challenges during emergencies.
Percentile ranking values range from 0 to 1, with higher values
indicating greater social vulnerability.
USAGE OF SVI
SVI can be used to:
- Assess community need during emergency preparedness planning
- Estimate the type and quantity of needed supplies such as food,
water, medicine, and bedding.
- Decide the number of emergency personnel required to assist
people.
- Identify areas in need of emergency shelters.
- Create a plan to evacuate people, accounting for those who have
special needs, such as those without vehicles, the elderly, or people
who do not speak English well.
- Identify communities that will need continued support to recover
following an emergency or natural disaster.
TABLE OF SOCIAL VULNEARBILITY INDEX INDICATORS
|
|
Total
|
|
|
(N=20)
|
|
Overall SVI Ranking
|
|
|
Mean (SD)
|
0.633 (0.208)
|
|
Median [Min, Max]
|
0.665 [0.221, 0.957]
|
|
% of Persons Aged 17 & Younger Estimate
|
|
|
Mean (SD)
|
13.7 (6.09)
|
|
Median [Min, Max]
|
15.0 [3.90, 22.8]
|
|
% of Persons age 65 & Older Estimate
|
|
|
Mean (SD)
|
17.1 (7.70)
|
|
Median [Min, Max]
|
16.3 [4.30, 37.3]
|
|
Occupied Housing Units with More People than Rooms % Estimate
|
|
|
Mean (SD)
|
1.49 (1.69)
|
|
Median [Min, Max]
|
0.900 [0, 7.00]
|
|
Civilian Population with a Disability % Estimate
|
|
|
Mean (SD)
|
13.8 (5.97)
|
|
Median [Min, Max]
|
13.2 [5.30, 31.1]
|
|
% of Persons in Group Quarters Estimate
|
|
|
Mean (SD)
|
3.07 (3.60)
|
|
Median [Min, Max]
|
1.25 [0, 14.1]
|
|
% of Housing Cost-Burdened
|
|
|
Mean (SD)
|
32.2 (7.80)
|
|
Median [Min, Max]
|
31.0 [20.5, 53.2]
|
|
Persons with limited English speaking % Estimate
|
|
|
Mean (SD)
|
2.50 (2.33)
|
|
Median [Min, Max]
|
1.65 [0, 8.20]
|
|
% of Minority
|
|
|
Mean (SD)
|
18.1 (8.04)
|
|
Median [Min, Max]
|
17.7 [8.20, 34.8]
|
|
% of Mobile Homes Estimate
|
|
|
Mean (SD)
|
0.320 (0.711)
|
|
Median [Min, Max]
|
0 [0, 2.60]
|
|
Housing with 10 or more Units % Estimate
|
|
|
Mean (SD)
|
21.9 (18.4)
|
|
Median [Min, Max]
|
15.5 [0.400, 73.5]
|
|
Persons (age 25+) with No High School Diploma % Estimate
|
|
|
Mean (SD)
|
4.98 (3.01)
|
|
Median [Min, Max]
|
3.80 [1.60, 10.8]
|
|
Households with No Vehicles % Estimate
|
|
|
Mean (SD)
|
16.2 (10.5)
|
|
Median [Min, Max]
|
12.4 [2.90, 43.2]
|
|
% of Persons below 150% Poverty Estimate
|
|
|
Mean (SD)
|
20.2 (8.35)
|
|
Median [Min, Max]
|
18.7 [6.50, 42.9]
|
|
% of Single-Parent Households with Children Under 18 Estimate
|
|
|
Mean (SD)
|
4.08 (3.27)
|
|
Median [Min, Max]
|
3.30 [0, 12.3]
|
|
Unemployment Rate Estimate
|
|
|
Mean (SD)
|
3.71 (2.68)
|
|
Median [Min, Max]
|
3.15 [0.600, 12.0]
|
|
Total Civilian Population with Insurance % Estimate
|
|
|
Mean (SD)
|
6.34 (3.11)
|
|
Median [Min, Max]
|
5.95 [2.00, 12.0]
|
SOCIAL VULNERABILITY INDEX OF PORTLAND CITY
OVERALL SOCIAL VULNEARBILITY INDEX
SOCIAL VULNERABILITY INDEX OF PORTLAND CITY
OVERALL SOCIAL VULNEARBILITY INDEX
AGE 17 & YOUNGER
AGE 65 & OLDER
CROWDING
DISABILITY
GROUP QUARTER
HOUSING COST BURDEN
LIMITED ENGLISH SPEAKING
MINORITY
MOBILE HOMES
MULTIPLE UNITS
NO HIGH SCHOOL DIPLOMA
NO VEHICLE
BELOW 150% POVERTY
SINGLE PARENT
UNEMPLOYMENT RATE
UNINSURED POPULATION
REFERENCES
CDC/ATSDR SVI
CDC SVI Documentation 2022